How to get sun streaks /lens flare effect in compositor?
So I found a solution to this problem I could of course use the Flares Wizard addon as @Jonas said yet the question was how it can be done with the compositor. This is how it can be done:

Add in a sphere which should be the sun
Give it an emission material with a strength of 10
Navigate to the object properties panel and in the relations -&gt;Change the pass index of the sphere to 1
Navigate to View layer properties and in the passes-&gt; enable object index (IndexOB)
Hit Render
Open up the compositor and use the node setup as shown:




Then you will get this:

PS:If your sphere is too big you will need to tweak the node setup.Likewise adding in a blur node in between can smoothen out that sharp streaks...
This is the rendered result:

If you want just sun glare you can you this node setup:
(Add node near render layers node is not necessary)
Which will get you this effect :

When adding the sun beams node make sure to place the cross in the middle of the sun